Laptop

[1][2] Most of the computer's internal hardware is in the lower part, under the keyboard, although many modern laptops have a built-in webcam at the top of the screen, and some even feature a touchscreen display.

Laptops are used in a variety of settings, such as at work (especially on business trips), in education, for playing games, web browsing, for personal multimedia, and for general home computer use.

They can run on both AC power and rechargable battery packs and can be folded shut for convenient storage and transportation, making them suitable for mobile use.

Portable computers, which later developed into modern laptops, were originally considered to be a small niche market, mostly for specialized field applications, such as in the military, for accountants, or travelling sales representatives.

A "personal, portable information manipulator" was imagined by Alan Kay at Xerox PARC in 1968,[7] and described in his 1972 paper as the "Dynabook".

[25] The development of memory cards was driven in the 1980s by the need for a floppy-disk-drive alternative, having lower power consumption, less weight, and reduced volume in laptops.

[40][5] Since the 1970s introduction of portable computers, their forms have changed significantly, resulting in a variety of visually and technologically differing subclasses.

There were in the past a number of marketing categories for smaller and larger laptop computers; these included "notebook" and "subnotebook" models, low cost "netbooks", and "ultra-mobile PCs" where the size class overlapped with devices like smartphone and handheld tablets, and "Desktop replacement" laptops for machines notably larger and heavier than typical to operate more powerful processors or graphics hardware.

All such devices have a touchscreen display designed to allow users to work in a tablet mode, using either multi-touch gestures or a stylus/digital pen.

A rugged laptop is designed to reliably operate in harsh usage conditions such as strong vibrations, extreme temperatures, and wet or dusty environments.

[46] The following sections summarize the differences and distinguishing features of laptop components in comparison to desktop personal computer parts.

[citation needed] The display interfaces with the motherboard using the embedded DisplayPort protocol via the Low-voltage differential signaling (LVDS) 30 or 40 pin connector.

These included netbooks, subnotebooks, ultra-mobile PC, and desktop replacement computers; these are sometimes still used informally, although they are generally not used anymore in manufacturer marketing.

Even on gaming models where unlocked processors are available, the cooling system in most laptops is often very close to its limits and there is rarely headroom for an overclocking–related operating temperature increase.

Higher-end laptops intended for gaming or professional 3D work still come with dedicated (and in some cases even dual) graphics processors on the motherboard or as an internal expansion card.

Apple's M series SoCs feature a unified pool of memory for both the system and the GPU; this approach can produce substantial efficiency gains for some applications but comes at the cost of eGPU support.

A touchpad (also called a trackpad), a pointing stick, or both, are used to control the position of the cursor on the screen, and an integrated keyboard[55] is used for typing.

Most laptops have webcams and microphones, which can be used to communicate with other people with both moving images and sound, via web conferencing or video-calling software.

The charger typically adds about 400 grams (0.88 lb) to the overall transporting weight of a laptop, although some models are substantially heavier or lighter.

Vendors may block charging if a power supply is not recognized as the original part, which could deny the legitimate use of universal third-party chargers.

Secondary device temperature monitoring may reduce performance or trigger an emergency shutdown if it is unable to dissipate heat, such as if the laptop were to be left running and placed inside a carrying case.

Although the trolleys can be moved between areas from one classroom to another, they can often be mounted or locked to the floor, support pillars, or walls to prevent thieves from stealing the laptops, especially overnight.

Some of the components of earlier models of laptops can easily be replaced without opening completely its bottom part, such as the keyboard, battery, hard disk, memory modules, and CPU cooling fan.

In some types, solder and glue are used to mount components such as RAM, storage, and batteries, making repairs additionally difficult.

The major brands usually offer good service and support, including well-executed documentation and driver downloads that remain available for many years after a particular laptop model is no longer produced.

[100] In the first quarter of 2002 in the United States market, Dell controlled 25.2% in the notebook space, well ahead of Toshiba (13.6%) and Compaq (11.7%), the latter of which had been acquired by Hewlett-Packard (HP).

[101] In Europe, the Middle East and Africa (EMEA) territories, Acer was the largest vendor of laptops, in 2004–2005, having overtaken HP and IBM there.

[115] The list of materials that go into a laptop computer is long, and many of the substances used, such as beryllium, lead, chromium, and mercury compounds, are toxic or carcinogenic to humans.

Similarly, the U.S. Environmental Protection Agency (EPA) has outlawed landfill dumping or the incinerating of discarded laptop computers.

Laptops used aboard the International Space Station and other spaceflights are generally the same ones that can be purchased by the general public but needed modifications are made to allow them to be used safely and effectively in a weightless environment such as updating the cooling systems to function without relying on hot air rising and accommodation for the lower cabin air pressure.